I think you missed the point. Prior to systemd, Debian was truly the universal operating system in the sense that it ran on just about anything, and you could swap out the kernel (not a trivial thing to do, but possible) for the FreeBSD kernel, for example. Because systemd is Linux-only, this is no longer possible. Because the list of smaller userspace utilities dependent on systemd is growing faster every day, it's likely that Debian will end up being no different from Arch, Fedora, RedHat, or Mandriva overall, apart from the package manager. Basically GNU/Linux is becoming GNU/systemd/Linux.

Some people don't have a problem with that, some do. In the end it's not about choosing an init system; indeed, I think a lot of the arguments and opposition to systemd would go away if systemd were interchangeable with any other init. But that's not the case; if your distro of choice has decided to go with systemd, then you're running systemd or you're not booting (yes, there are shims in Debian right now but they exist only for migration purposes).